BCCB2000 Lecture 10 Questions Flashcards
(29 cards)
Polysaccharides can vary in their monomer composition and the type of bond between monomers. True or False?
True
Is the following statement and reason true? Is the reason the correct explanation of the statement? Statement: Patients suffering or recovering from severe diarrhorea are advised not to drink or eat diary products. Reason: Disaccharidases are lost during diarrhorea causing a temporary acquired enzyme deficiency.
Statement is True; Reason is True; the reason is a correct explanation of the statement
The orientation of ‘non-reducing to reducing’ ends gives a disaccharide a direction not unlike the direction of a polypeptide chain from N-terminal to C-terminal True or False?
True
When two carbohydrates are epimers: A. they rotate plane-polarized light in the same direction B. they differ in length by one carbon C. one is an aldose, the other a ketose D. one is a pyranose, the other a furanose E. they differ only in the configuration around one carbon atom
E. they differ only in the configuration around one carbon atom
Which of the following pairs is interconverted in the process of mutarotation? A. α-D-glucose and β-D-glucose B. D-glucose and L-glucose C. D-glucose and D-fructose D. D-glucose and D-glucosamine
A. α-D-glucose and β-D-glucose
Which is not a glycoconjugate? A. Proteoglycan B. Glycolipid C. Glycoprotein D. homoglycan
D. homoglycan
Which of the following is a homopolysaccharide of glucose and is found exclusively in animal cells? A. starch B. heteropolysaccharide C. glucagon D. glycogen
D. glycogen
Which of following is an anomeric pair? A. D-glucose and L-glucose B. D-glucose and D-fructose C. α-D-glucose and β-D-glucose D. α-D-glucose and β-L-glucose E. D-glucose and L-fructose
C. α-D-glucose and β-D-glucose
Carbohydrate anomers can be interconverted ________.
via a linear intermediate
In glycoproteins, the carbohydrate moiety is always attached through the amino acid residues: A. tryptophan, aspartate, or cysteine. B. asparagine, serine, or threonine. C. glycine, alanine, or aspartate. D. aspartate or glutamate. E. glutamine or arginine.
B. asparagine, serine, or threonine.
Maltose is a disaccharide comprised of the following two monosaccharides. A. fructose and glucose B. glucose and glucose C. glucose and galactose D. mannose and fructose E. ribose and glucose
B. glucose and glucose
In solution α-D-glucopyranose and β-D-glucopyranose ________. A. rapidly polymerize to form a heteropolymer B. can never exist together C. form a racemic mixture D. form an equilibrium mixture
D. form an equilibrium mixture
Which statement about cellulose is false? A. It is the most abundant polysaccharide in nature. B. Its monomers are joined by glycosidic bonds. C. It is present in the stems of flowering plants. D. The hydroxyl groups of neighboring cellulose molecules interact to form strong, insoluble fibers. E. It is a branched polymer of glucose.
E. It is a branched polymer of glucose.
Which is true about naturally occurring monosaccharides? A. The L-isomers predominate. B. The D-isomers predominate. C. The L and D-isomers occur in equal ratios. D. The ratio of L and D-isomers varies widely depending on the source.
B. The D-isomers predominate.
Lactose is a disaccharide comprised of the following two monosaccharides. A. fructose and glucose B. glucose and galactose C. glucose and glucose D. ribose and glucose E. mannose and fructose
B. glucose and galactose
In some monosaccharides the carbonyl oxygen can be reduced to a hydroxyl group. For example, D-glyceraldehyde can be reduced to glycerol. However, after being reduced this sugar no longer has the designation D or L. Why? A. the functional groups at C1 and C3 are different after the reaction. B. the molecule is chiral after the reaction C. the functional groups at C1 and C3 are the same after the reaction. D. the epimer of glyceraldehyde is different after the reaction E. the anomer of glyceraldehyde is different after the reaction
C. the functional groups at C1 and C3 are the same after the reaction.
Which of the following is an epimeric pair? A. D-glucose and D-mannose B. D-lactose and D-sucrose C.D-glucose and D-glucosamine D. L-mannose and L-fructose E. D-glucose and L-glucose
A. D-glucose and D-mannose
The reference compound for naming D and L isomers of sugars is: A. glucose B. glyceraldehyde C. ribose D. fructose E. sucrose
B. glyceraldehyde
From the abbreviated name of the compound Galβ(1–>4)Glc, we know that: A. the glucose residue is the β anomer. B. the galactose residue is at the reducing end. C. C-4 of glucose is joined to C-1 of galactose by a glycosidic bond. D. the compound is a D-enantiomer. E. the glucose is in its pyranose form.
C. C-4 of glucose is joined to C-1 of galactose by a glycosidic bond.
Which of the following statements best describes glucose? A. Homopolysaccharides of glucose, formed by the action of glycosyltransferases are always branched molecles that contain only beta-glycosidic linkages. B. It is utilized in biological systems only in the L-isomeric form C. It is produced from dietary starch by the action of alpha amylase D. It is a C-4 epimer of galactose E. It is a ketose and usually exists as a furanose ring in solution
D. It is a C-4 epimer of galactose
Polysaccharides can vary in their chain length, extent of branching, and biological function True or False?
True
To possess optical activity, a compound must be: A. colored. B. a carbohydrate. C. asymmetric. D. D-glucose. E. a hexose.
C. asymmetric.
Which of the following is a heteropolysaccharide? A. glycogen B. hyaluronate C. starch D. cellulose E. chitin
B. hyaluronate
Which of the following glycosidic bonds is hydrolysed by α-amylase? A. β(1—>4) B. α(1—>4) C. β(1—>4) D. α(1—>6)
B. α(1—>4)
